[ovs-dev] [PATCH v2 1/2] lib/netdev-dpdk: make device name parsing more robust

[Mauricio Vasquez B]

Current implementation of dpdk_dev_parse_name does not perform a robust
error handling, port names as "dpdkr", "dpdkr1x", "dpdkr 5" are considered
valid.

With this path only positive port numbers in decimal notation are considered
valid.

Signed-off-by: Mauricio Vasquez B <mauricio.vasquezbernal at studenti.polito.it>
---
v2:
- replace strtol by strtoul
- more strict parsing, ports as "dpdr 5" are now not valid.
Thanks to Aaron Conole!
 lib/netdev-dpdk.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index de7e488..5d09230 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -18,7 +18,9 @@
 
 #include <string.h>
 #include <signal.h>
+#include <ctype.h>
 #include <stdlib.h>
+#include <limits.h>
 #include <pthread.h>
 #include <config.h>
 #include <errno.h>
@@ -187,7 +189,7 @@ struct dpdk_ring {
     /* For the client rings */
     struct rte_ring *cring_tx;
     struct rte_ring *cring_rx;
-    int user_port_id; /* User given port no, parsed from port name */
+    unsigned int user_port_id; /* User given port no, parsed from port name */
     int eth_port_id; /* ethernet device port id */
     struct ovs_list list_node OVS_GUARDED_BY(dpdk_mutex);
 };
@@ -636,18 +638,42 @@ unlock:
     return err;
 }
 
+/* dev_name must be the prefix followed by a positive decimal number.
+ * (no leading + or - signs are allowed) */
 static int
 dpdk_dev_parse_name(const char dev_name[], const char prefix[],
                     unsigned int *port_no)
 {
     const char *cport;
+    unsigned long port;
+    char *endptr;
 
     if (strncmp(dev_name, prefix, strlen(prefix))) {
         return ENODEV;
     }
 
+    errno = 0;
     cport = dev_name + strlen(prefix);
-    *port_no = strtol(cport, NULL, 0); /* string must be null terminated */
+
+    if(!isdigit(cport[0])) {
+        return ENODEV;
+    }
+
+    port = strtoul(cport, &endptr, 10);
+
+    if(errno != 0) {
+        return errno;
+    }
+
+    if(endptr == NULL || *endptr != '\0' || endptr == cport) {
+        return ENODEV;
+    }
+
+    if(port > UINT_MAX) {
+        return ENODEV;
+    }
+
+    *port_no = port;
     return 0;
 }
 
-- 
1.9.1